Mechanistic Studies of Proton‐Donor Coordination to Samarium Diiodide

Three's a crowd: Initial coordination of diethylene glycol to SmI2 liberates THF or iodide, thus providing open coordination sites for substrates and enhancing reactivity. Concentrations of diethylene glycol that lead to coordinative saturation of SmI2 (see structure) reduce its reactivity. Replacement of a hydroxy proton with a methyl group decreases the affinity of the chelate for SmI2, resulting in a decrease in the reactivity of the complex.